The present invention relates to a brake triggering device for an elevator car, by means of which brake devices disposed at both sides of a car structure are actuated by a limiter cable and an entraining lever by way of a transmission element and a trigger element.
It is known that brake devices for elevator cars are actuated by the limiter cable and an entraining lever by way of a linkage. The linkage connects in a known manner and in a crosswise mode the two brake devices disposed laterally of the elevator car.
The European patent specification 0 498 597 discloses a brake device similar to the above-described kind. A limiter cable is connected with the entraining lever at the elevator car, which lever in turn actuates the brake device opposite the entraining lever by way of tensioned connecting cables arranged crosswise and replacing a linkage. Since the brake devices in this known apparatus, as is often usual, are disposed at the underside of the elevator car, they are actuated by the connecting cables by way of upwardly and downwardly arranged parallel rockers similarly connected with the cables.
In the case of the above-mentioned trigger device, the triggering of the brake device takes place by way of several transmission elements, thus indirectly. In addition, the connecting cables must permanently be in a tightly tensioned state, which can lead to high bearing loadings and greater friction losses. Moreover, all transmission elements must transmit the full engaging force for the braking devices. Due to the greater transmission path for the brake device disposed opposite the entraining lever, an absolutely synchronous engaging of the two brake devices is not guaranteed.
In general, with the known solutions a specific delay time between the blocking of the limiter cable by the responding limiter and the effective action of the brake devices results, because the entraining lever must cover a relatively large path for that purpose.